package com.stfalcon.chatkit.sample.utils;

import android.util.Log;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.security.Key;
import java.util.Arrays;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class SM4 {


    private static final int ENCRYPT = 1;
    private static final int DECRYPT = 0;
    public static final int ROUND = 32;
    private static final int BLOCK = 16;

    private byte[] Sbox = {
            (byte) 0xd6, (byte) 0x90, (byte) 0xe9, (byte) 0xfe, (byte) 0xcc, (byte) 0xe1, 0x3d, (byte) 0xb7, 0x16, (byte) 0xb6, 0x14, (byte) 0xc2, 0x28, (byte) 0xfb, 0x2c, 0x05,
            0x2b, 0x67, (byte) 0x9a, 0x76, 0x2a, (byte) 0xbe, 0x04, (byte) 0xc3, (byte) 0xaa, 0x44, 0x13, 0x26, 0x49, (byte) 0x86, 0x06, (byte) 0x99,
            (byte) 0x9c, 0x42, 0x50, (byte) 0xf4, (byte) 0x91, (byte) 0xef, (byte) 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43, (byte) 0xed, (byte) 0xcf, (byte) 0xac, 0x62,
            (byte) 0xe4, (byte) 0xb3, 0x1c, (byte) 0xa9, (byte) 0xc9, 0x08, (byte) 0xe8, (byte) 0x95, (byte) 0x80, (byte) 0xdf, (byte) 0x94, (byte) 0xfa, 0x75, (byte) 0x8f, 0x3f, (byte) 0xa6,
            0x47, 0x07, (byte) 0xa7, (byte) 0xfc, (byte) 0xf3, 0x73, 0x17, (byte) 0xba, (byte) 0x83, 0x59, 0x3c, 0x19, (byte) 0xe6, (byte) 0x85, 0x4f, (byte) 0xa8,
            0x68, 0x6b, (byte) 0x81, (byte) 0xb2, 0x71, 0x64, (byte) 0xda, (byte) 0x8b, (byte) 0xf8, (byte) 0xeb, 0x0f, 0x4b, 0x70, 0x56, (byte) 0x9d, 0x35,
            0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, (byte) 0xd1, (byte) 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, (byte) 0x87,
            (byte) 0xd4, 0x00, 0x46, 0x57, (byte) 0x9f, (byte) 0xd3, 0x27, 0x52, 0x4c, 0x36, 0x02, (byte) 0xe7, (byte) 0xa0, (byte) 0xc4, (byte) 0xc8, (byte) 0x9e,
            (byte) 0xea, (byte) 0xbf, (byte) 0x8a, (byte) 0xd2, 0x40, (byte) 0xc7, 0x38, (byte) 0xb5, (byte) 0xa3, (byte) 0xf7, (byte) 0xf2, (byte) 0xce, (byte) 0xf9, 0x61, 0x15, (byte) 0xa1,
            (byte) 0xe0, (byte) 0xae, 0x5d, (byte) 0xa4, (byte) 0x9b, 0x34, 0x1a, 0x55, (byte) 0xad, (byte) 0x93, 0x32, 0x30, (byte) 0xf5, (byte) 0x8c, (byte) 0xb1, (byte) 0xe3,
            0x1d, (byte) 0xf6, (byte) 0xe2, 0x2e, (byte) 0x82, 0x66, (byte) 0xca, 0x60, (byte) 0xc0, 0x29, 0x23, (byte) 0xab, 0x0d, 0x53, 0x4e, 0x6f,
            (byte) 0xd5, (byte) 0xdb, 0x37, 0x45, (byte) 0xde, (byte) 0xfd, (byte) 0x8e, 0x2f, 0x03, (byte) 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
            (byte) 0x8d, 0x1b, (byte) 0xaf, (byte) 0x92, (byte) 0xbb, (byte) 0xdd, (byte) 0xbc, 0x7f, 0x11, (byte) 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, (byte) 0xd8,
            0x0a, (byte) 0xc1, 0x31, (byte) 0x88, (byte) 0xa5, (byte) 0xcd, 0x7b, (byte) 0xbd, 0x2d, 0x74, (byte) 0xd0, 0x12, (byte) 0xb8, (byte) 0xe5, (byte) 0xb4, (byte) 0xb0,
            (byte) 0x89, 0x69, (byte) 0x97, 0x4a, 0x0c, (byte) 0x96, 0x77, 0x7e, 0x65, (byte) 0xb9, (byte) 0xf1, 0x09, (byte) 0xc5, 0x6e, (byte) 0xc6, (byte) 0x84,
            0x18, (byte) 0xf0, 0x7d, (byte) 0xec, 0x3a, (byte) 0xdc, 0x4d, 0x20, 0x79, (byte) 0xee, 0x5f, 0x3e, (byte) 0xd7, (byte) 0xcb, 0x39, 0x48
    };

    private int[] CK = {
            0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
            0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
            0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
            0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
            0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
            0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
            0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
            0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
    };

    private int Rotl(int x, int y) {
        return x << y | x >>> (32 - y);
    }

    private int ByteSub(int A) {
        return (Sbox[A >>> 24 & 0xFF] & 0xFF) << 24 | (Sbox[A >>> 16 & 0xFF] & 0xFF) << 16 | (Sbox[A >>> 8 & 0xFF] & 0xFF) << 8 | (Sbox[A & 0xFF] & 0xFF);
    }

    private int L1(int B) {
        return B ^ Rotl(B, 2) ^ Rotl(B, 10) ^ Rotl(B, 18) ^ Rotl(B, 24);
        //	return B^(B<<2|B>>>30)^(B<<10|B>>>22)^(B<<18|B>>>14)^(B<<24|B>>>8);
    }

    private int L2(int B) {
        return B ^ Rotl(B, 13) ^ Rotl(B, 23);
        //	return B^(B<<13|B>>>19)^(B<<23|B>>>9);
    }

    void MySm4Crypt(byte[] Input, byte[] Output, int[] rk) {
        int r, mid, x0, x1, x2, x3;
        int[] x = new int[4];
        int[] tmp = new int[4];
        for (int i = 0; i < 4; i++) {
            tmp[0] = Input[0 + 4 * i] & 0xff;
            tmp[1] = Input[1 + 4 * i] & 0xff;
            tmp[2] = Input[2 + 4 * i] & 0xff;
            tmp[3] = Input[3 + 4 * i] & 0xff;
            x[i] = tmp[0] << 24 | tmp[1] << 16 | tmp[2] << 8 | tmp[3];
            //	x[i]=(Input[0+4*i]<<24|Input[1+4*i]<<16|Input[2+4*i]<<8|Input[3+4*i]);
        }
        for (r = 0; r < 32; r += 4) {
            mid = x[1] ^ x[2] ^ x[3] ^ rk[r + 0];
            mid = ByteSub(mid);
            x[0] = x[0] ^ L1(mid);   //x4
            mid = x[2] ^ x[3] ^ x[0] ^ rk[r + 1];
            mid = ByteSub(mid);
            x[1] = x[1] ^ L1(mid);    //x5
            mid = x[3] ^ x[0] ^ x[1] ^ rk[r + 2];
            mid = ByteSub(mid);
            x[2] = x[2] ^ L1(mid);    //x6
            mid = x[0] ^ x[1] ^ x[2] ^ rk[r + 3];
            mid = ByteSub(mid);
            x[3] = x[3] ^ L1(mid);    //x7
        }
        //Reverse
        for (int j = 0; j < 16; j += 4) {
            Output[j] = (byte) (x[3 - j / 4] >>> 24 & 0xFF);
            Output[j + 1] = (byte) (x[3 - j / 4] >>> 16 & 0xFF);
            Output[j + 2] = (byte) (x[3 - j / 4] >>> 8 & 0xFF);
            Output[j + 3] = (byte) (x[3 - j / 4] & 0xFF);
        }
    }

    private void MySm4KeyExt(byte[] Key, int[] rk, int CryptFlag) {
        int r, mid;
        int[] x = new int[4];
        int[] tmp = new int[4];
        for (int i = 0; i < 4; i++) {
            tmp[0] = Key[0 + 4 * i] & 0xFF;
            tmp[1] = Key[1 + 4 * i] & 0xff;
            tmp[2] = Key[2 + 4 * i] & 0xff;
            tmp[3] = Key[3 + 4 * i] & 0xff;
            x[i] = tmp[0] << 24 | tmp[1] << 16 | tmp[2] << 8 | tmp[3];
            //	x[i]=Key[0+4*i]<<24|Key[1+4*i]<<16|Key[2+4*i]<<8|Key[3+4*i];
        }
        x[0] ^= 0xa3b1bac6;
        x[1] ^= 0x56aa3350;
        x[2] ^= 0x677d9197;
        x[3] ^= 0xb27022dc;
        for (r = 0; r < 32; r += 4) {
            mid = x[1] ^ x[2] ^ x[3] ^ CK[r + 0];
            mid = ByteSub(mid);
            rk[r + 0] = x[0] ^= L2(mid);        //rk0=K4
            mid = x[2] ^ x[3] ^ x[0] ^ CK[r + 1];
            mid = ByteSub(mid);
            rk[r + 1] = x[1] ^= L2(mid);        //rk1=K5
            mid = x[3] ^ x[0] ^ x[1] ^ CK[r + 2];
            mid = ByteSub(mid);
            rk[r + 2] = x[2] ^= L2(mid);        //rk2=K6
            mid = x[0] ^ x[1] ^ x[2] ^ CK[r + 3];
            mid = ByteSub(mid);
            rk[r + 3] = x[3] ^= L2(mid);        //rk3=K7
        }
        //解密时轮密钥使用顺序：rk31,rk30,...,rk0
        if (CryptFlag == DECRYPT) {
            for (r = 0; r < 16; r++) {
                mid = rk[r];
                rk[r] = rk[31 - r];
                rk[31 - r] = mid;
            }
        }
    }

    /**
     * SM4的加密、解密
     *
     * @param in        如果是加密则代表明文，如果是解密则代表密文
     * @param inLen     字节长度
     * @param key       密钥
     * @param out       运算结果，如果是加密返回的是密文，如果是解密则返回的是明文
     * @param CryptFlag 1加密 0解密
     * @return
     */
    public int EnOrDecrypt(byte[] in, int inLen, byte[] key, byte[] out, int CryptFlag) {
        int point = 0;
        int[] round_key = new int[ROUND];
        //int[] round_key={0};
        MySm4KeyExt(key, round_key, CryptFlag);
        byte[] input = new byte[16];
        byte[] output = new byte[16];
        while (inLen >= BLOCK) {
            input = Arrays.copyOfRange(in, point, point + 16);
            //output=Arrays.copyOfRange(out, point, point+16);
            MySm4Crypt(input, output, round_key);
            System.arraycopy(output, 0, out, point, BLOCK);
            inLen -= BLOCK;
            point += BLOCK;
        }
        return 0;
    }

    /**
     * string 转 16进制
     *
     * @param src
     * @return
     */
    public static byte[] getString2HexBytes(String src) {
        byte[] ret = new byte[src.length() / 2];
        byte[] tmp = src.getBytes();
        for (int i = 0; i < src.length() / 2; i++) {
            ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);
        }
        return ret;
    }

    /**
     * 将两个ASCII字符合成一个字节；
     * 如："EF"--> 0xEF
     *
     * @param src0 byte
     * @param src1 byte
     * @return byte
     */
    public static byte uniteBytes(byte src0, byte src1) {
        try {
            byte b0 = Byte.decode("0x" + new String(new byte[]{src0})).byteValue();
            b0 = (byte) (b0 << 4);
            byte _b1 = Byte.decode("0x" + new String(new byte[]{src1})).byteValue();
            byte ret = (byte) (b0 ^ _b1);
            return ret;
        } catch (Exception e) {
            Log.i("Tag", e.getMessage());
        }
        return 0;
    }

    public static String bytesToHexString(byte[] bArr) {
        StringBuffer sb = new StringBuffer(bArr.length);
        String sTmp;

        for (int i = 0; i < bArr.length; i++) {
            sTmp = Integer.toHexString(0xFF & bArr[i]);
            if (sTmp.length() < 2)
                sb.append(0);
            sb.append(sTmp.toUpperCase());
        }

        return sb.toString();
    }


    /**
     * SM4算法的ECB模式的加密、解密
     * 注意：ECB模式下没有IV（偏移量）
     * 注意：SM4的密钥长度必须为16个字节，数据长度必须为16的整数倍
     *
     * @param dataBytes 如果是加密则代表明文，如果是解密则代表密文
     * @param keyBytes  密钥，固定为16个字节
     * @param mode      加/解密
     * @return 如果是加密返回的是密文，如果是解密则返回的是明文
     * @throws Exception
     */
    public static byte[] Sm4EnOrDecrypt_EcbMode(byte[] dataBytes, byte[] keyBytes, int mode) throws Exception {
        Cipher cipher = Cipher.getInstance("SM4/ECB/NoPadding", new BouncyCastleProvider());
        Key key = new SecretKeySpec(keyBytes, "SM4");
        cipher.init(mode, key);
        return cipher.doFinal(dataBytes);
    }
}